Rosin size and method of preparing same and paper sized therewith



3,251,732 ROSIN SIZE AND METHOD F PREPARING SAME AND PAPER SIZED THEREWITH Paul H. Aldrich, Wilmington, Del., assignor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware No Drawing. Filed Sept. 6, 1962, Ser. No. 221,875 18 Claims. (Cl. 162-479) This invention relates to novel rosin size compositions and to the preparation and use of same for sizing paper, paperboard and the like.

It is known that small amounts of higher fatty acids in rosin size, i.e., sizes from tall oil rosin, do not-materially detract from sizing, However, as the fatty acid content increases above about 3%, sizing efi'iciency is adversely atfected. Because of this, it has always been considered necessary to reduce the fatty acid content of rosin below about 3% and preferably below 1%. This is diflicult and expensive and adds substantially to the cost of the product.

A principal object of the invention is the provision of a sizing composition made from rosin and from about 3% to about 13% by Weight, based on the weight of rosin, of higher fatty acids, said sizing composition being equivalent in sizing efliciency to ordinary rosin size.

A further object of the invention is the provision of paste rosin sizes which have lower than normal viscosities.

Another object of the invention is the incorporation of fatty acids with rosin used in the preparation of rosin size in amounts two or three times greater than the maximum hitherto thought possible without substantial decrease in sizing efiiciency of the resulting sizes.

Still another object of the invention is the provision of a method of converting mixtures of rosin and fatty acids to rosin size having at least as good sizing efiiciency as ordinary rosin size.

It has now been discovered that the objects of the invention can be attained by reacting a mixture of rosin and higher fatty acids with sufiicient amounts of certain polyhydric alcohols or high molecular weight polycyclic monohydric alcohols to substantially completely esterify the higher fatty acids present in the mixture and then partially or substantially completely neutralizing the resulting product with aqueous alkali. These sizes are characterized by an original fatty acid content of from about 3% to about 13% by weight, based on the weight of rosin, the bulk of this fatty acid content ultimately being present in the form of an ester. These sizes are further characterized by lower viscosities than the usual paste rosin sizes.

The rosin sizes of the invention can be prepared from various types of rosin including gum rosin, wood rosin, and'tall oil rosin, as well as modified rosins such as partially and/or substantially completely hydrogenated rosins, disproportionated rosins, and polymerized rosius. Fortified rosins, i.e., rosins which have been reacted with from about one-twentieth to one mole per mole of rosin of an aliphatic dibasic acidic dienophile containing the group such as maleic, fumaric, itaconic, aconitic, and the like acids and anhydrides, can also be used.

The fatty acids contemplated for use herein are the aliphatic, monocarboxylic acids having from about 14 to about 26 carbon atoms and mixtures of same. Fatty acid mixtures of this type which are quite satisfactory for use herein are various mixtures of fatty acids and fatty acid fractions derived from tall oil. A typical analysis of a United States Patent 0 Patented May 17, 1966 fatty acid fraction obtained by the fractional distillation of tall oil is as follows:

Percent Palrnitic acid 5.7 Palmitoleic acid L5 Stearic acid 1.4 Oleic acid 30.7 Linoleic acid 42.4 Eicosanoic acid 7.0 Doersanoic acid 2.5 Linolenic acid 1.5

Depending upon the tall oil source, the method of fractional distillation and the fraction taken, there will also be greater or lesser amounts of C and C and C to C acids. These acids can be unsaturated or saturated, straight or branched chained. Furthermore, the amounts of linoleic and oleic acids can each vary from about 5% oil and various fractions thereof containing mixtures of resin acids and fatty acids can be used as the source of the rosin and fatty acids used in the compositions of the invention. Various blends of mixtures of rosin and fatty acids may also be made by combining rosin and fatty acids in various proportions.

The esterification of the fatty acids can be carried out with polyhydric alcohols such as pentaerythritol, dipentaerythritol, polypentaerythritols, glycerol, trimethylolethane and trimethylolpropane, or with high molecular weight polycyclic monohydric alcohols such as hydroabietyl alcohols, e.g., Abitol, a mixture of tetra-, di-, and dehydroabietyl alcohols made from rosin, and beta-sitosterol.

Mixtures of these alcohols can also be used.

In preparing the sizes of the invention from a mixture of, for example, tall oil rosin and fatty acids the mixture containing from about 3% to about 13% by weight, based on the weight of rosin, of higher fatty acids is esterified with the polyhydric alcohol or high molecular weight polycyclic monohydric alcohol until at least 50% by weight, based on the weight of fatty acids present plus a small amount of rosin acids in said mixture, is converted to the corresponding fatty acid esters. The product is then neutralized with aqueous alkali, e.g., sodium or potassium hydroxide or carbonate. In the case of paste size, sufficient alkali is used to neutralize from about 70% to about of the acidity of the rosin. However, if the paste size is to be converted to a dry size, substantially complete, e.g., neutralization is preferred.

The esterification reaction can be carried out at temperatures from about C. to about 250 C. However, it is preferred to operate within the range from about 180 C. to about 230 C. The time of reaction will vary with the temperature, the reactants, and so on and, in general, will be from about 2 hours to about 10 hours. For optimum results, the reaction is continued until the acid number stops decreasing or nearly stops and is substantially constant. The reaction can be carried out with no catalyst or with'such acidic catalysts as sulfuric, hydrochloric, phosphoric, para-toluene sulfonic acid, acetic acid, and other inorganic and organic acids or other basic catalysts as calcium oxide as are well known to those versed in the art. If an acid catalyst is 3 used, the preferred temperature range of the reaction can be lowered to about 150 C. thereby minimizing any possibility of decarboxylation of the rosin and dehydration of susceptible alcohols.

The partial neutralization of the mixture of rosin and esterified watty acids referred toabove can be carried out by adding aqueous alkali metal hydroxide of carbonate to the molten mixture and then heating at temperatures from about 90 C. to about 110 C. until the caustic has substantially completely reacted.

An alternative method ofpreparation of the sizes is the blending of two or more paste sizes, one made by the neutralization of untreated rosin and the other or others made by the partial neutralization of a reaction product of a polyhydric or polycyclic monohydric alcohol and a mixture of higher fatty acids and rosin. The proportions of the bland are adjusted to give a final content of fatty acid of about 3% to 13% based on the weight of the rosin.

Another method of preparation of the sizes is the partial neutralization of a blend of untreated rosin and the reaction product of a polyhydric or polycyclic monohydric alcohol and a mixture of higher fatty acids and rosin. The proportions of the two rosins are adjusted so that .the fatty acid content of the blend would lie between 3% and 13%, based-on the weight of the rosin.

The sizes of the invention can also be prepared, in most cases, by esterifying a higher fatty acid or mixture of higher fatty acids, adding an amount of the esterified acid or esterified mixture of acids, such that the weight of the fatty acid portion of the ester is 3% to 13% of the weight of the rosin, to rosin, and then partially neutralizing as described above. However, in this case, emulsifiability of the resulting size may be inferior to that obtained when the fatty acid is reacted in the presence of rosin.

The amount of polyhydric alcohol or polycyclic monohydric alcohol utilized in preparing the compositions of the invention desirably is such as to substantially completely esterify the fatty acids present in the mixture. This will generally require those amounts of polyhydric alcohols or polycyclic monohydric alcohols which will sup-. ply an amount of hydroxyl equivalent to the amount of fatty acid carboxyl plus an additional amount because some rosin also reacts. The ratio of equivalents of hydroxyl to fatty acid carboxyl may vary from about .8 to about 2. Optimum results, in terms of sizing efficiency, are obtained if the amount of polyhydric alcohol or polycyclic monohydric alcohol is in excess of that theoretically required to esterify the fatty acids. For this reason, it is most preferred to use an amount of polyhydric alcohol or polycyclic monohydric alcohol which exceeds that theoretically required to esterify the fatty acids by from about 5% to about 20%.

The paste rosin sizes of the invention can be prepared at any desired solids content, i.e., from about 50% to about 80% total solids, but will usually be prepared with total solids of from about 70% to about 80%. These paste rosin sizes are readily converted to primary emulsions containing from about 6% to about 20% solids by adding water at 25100 C. These can be mixed with cold water to form stable, dilute, secondary emulsions con- .taining from about 1% to about 5% solids.

In the manufacture of dry sizes in accordance with the invention, essentially the same procedure can be follower as used in the preparation of the paste size except that the product is preferably substantially completely neutralized rather than only partially neutralized. The resulting pastes can then be dehydrated as by spray drying to form the dry sizes.

In the sizing of paper in accordance with the invention, the novel sizes herein described are added to an aqueous pulp suspension, as in the beater of a papermaking system or at any other point prior to web forma- -tion, the dry size being added as such or in an aqueous dispersion, and the paste size being added in the form of a dilute, aqueous emulsion. The size is added in an amount sufficient to supply from about 0.25% to about 5% by weight, based on .the weight of dry pulp, of solids. num sulfate or like fixing agent is added in suitable amounts, e.g., from about 1% to about 5% by weight, based on the weight of dry pulp, and the pulp then sheeted and dried in the usual manner.

The following examples will further illustrate the invention:

Example 1 A mixture of 4415 parts of tall oil rosin (acid number 164.0, percent rosin acids 83.5, percent fatty acids 4.6, percent neutrals 6.5), 58.5 parts of tall oil fatty acids (acid number 191.3, percent rosin acids 3.5, and per- 1 cent fatty acids 92.9) and 8.14 parts (the stoichiometric quantity necessary to esterify all the fatty acid) of glycerin was heated to 200 C., stirred for 420 minutes, and then cooled to room temperature. The product had the following analyses:

Acid number 129.0

Rosin acids, percent 62.3

Fatty acids, percent 6.8

Neutrals, percent 20.5

Example 2 Using the method of Example 1, 441.5 parts of a tall oil rosin (same as Example 1), 58.5 parts of tall oil fatty acids (same as Example 1), and 9.02 parts of Hercules pentaerythritol (the stoichiometric quantity) were reacted. The product analyzed as follows:

Acid number 131.1 Rosin acids, percent 68.5 Fatty acids, percent 2.0 Neutrals, percent 19.4-

Example 3 Acid number 114.3 Resin acids, percent 60.8 Fatty acids, percent 0.8 Neutrals, percent 33.0

Example 4 Using the method of Example 1, 441.5 parts of a tanoil rosin (same as Example 1), 58.5 parts of tall oil fatty acid (same as Example 1), and 1 09.6 parts (the stoichiometric quantity) of sitosterol (General Mills) were reacted. The product analyzed as follows:

Acid number 112.8 Resin acids, percent 58.4 Fatty acids, percent 2.2 Neutrals, percent 30.6

Example 5 Using the method of Example 1, 441.5 parts of a tall oil rosin (same as Example 1), 58.5 parts of a tall oil fatty acid (same as Example 1), and 8.94 parts (10% excess over the stoichiometric quantity necessary to After thoroughly beating the mixture, alumi- 5 esterify all the fatty acid) of glycerol were reacted. The analyses of the product are as follows:

Using the method of Example 1, 441.5 parts of a tall oil rosin (same as Example 1), 58.5 parts of a tall oil fatty acid (same as Example 1), and 9.9 parts (10% excess) of Hercules pentaeryt hritol were reacted. The product analyzed as follows:

Acid number 133.6 Resin acids, percent a 20.4 Fatty acids, percent 1.5 Neutrals, percent 19.0

Example 7 Using the method of Example 1, 441.5 parts of tall oil rosin (same as Example 1), 585' parts of tall oil fatty acid (same as Example 1), and 113.8 parts (10% excess) of Hercules Abitol (registered trademark) were reacted. The product analyzed as follows:

Acid number 106.2

Resin acids, percent 58.4

Fatty acids, percent Neutrals, percent I 36.0

Example 8 Using the method of Example 1, 441.5 parts of a tall oil rosin (same as Example 1), 58.5 parts of tall oil fatty acid (same as Example 1), and 120.5 parts.(1'0% excess) of sitosterol (General Mills) were reacted. The

Examples 9-17 Sizes were made from the resins of Examples 1-8 by melting the resin and adding aqueous caustic to give about 70% total solids and 20-23 acid number. In addition, for use as an experimental size component, a size of wood rosin (acid number 166.5, percent neutrals 6.8)

was similarly prepared. The .total solids of each size and the resin used in the preparation are summarized in Table 1.

TABLE 1 Total Size Resin Source Alcohol Used in Resin Solids,

Percent Example 9..-. Example 1- Glycerol (stoichiometric) 70. 1 Example 10--. Example 2-.-- Pentstileirythritol (stoichio- 70. 4

' me o Example 11 Example 3 Abitol (stoichiometrie) 70. 4 Example 12--. Example 4 Sitosterol (stoichiometric 70.1 Example 13.-. Example Glycerol excess) 70. 5 Example 14". Example 6 Pentzzerssthritol (stoichio- 70. 4

me no Example 15.-. Example 7 Abitol (stoichiometric) 70. 0 Example 16- Example 8. Sitosterol (stoichi0metric) 70. 7 Example 17-.. Wood Rosin-.- 69. 5

Example 18 The Diels-Alder adduct of rosin and fumaric acid was prepared by heating together at 200 C. for 3 /2 hours 2,000 parts of a wood rosin (same as Example 17) and 380 parts of fumaric acid. This product was converted to a size by adding itin pulverized form to a stirred solution of hot caustic. The resultant size had total solids of 69.1% and an acid number of 19.2.

Examples 19-34 Each 7 TABLE 2 Reaction Product Parts Parts Parts Size Blend From Which Size Reaction Example Example Is Derived Product 17 18 Size Example 19 Example 9 49. 1 Example 20 Example 10.. 47. 3 Example 21 Example 11 58.0 Example 22 Example 1 59. 0 Example 23. Example 1 48. 9 Example 24- Example 14 49. 1 Example 25 Example 15 59. 4 Example 26..;.. Example 16 59.4 Example 27 Example 9 49. 1 Example 28- Example 10-. 49. 0 Example 29- Example 11 58. 0 Example 30-.. Example 12 59. 0 Example 31"--. Example 13 48. 9 Example 32 Example 14 49. 1 Example 33 Example 15 59. 4 Example 34 Example 16 59. 4

Example 35 A blend of tail oil rosin (same as Example 1) and tall oil fatty acids (same as Example 1) containing 10% uncombined fatty acid was made into a size according to the method of Examples 9-17.

Example 36 A blend of tall oil rosin (same as Example 1), tall oil fatty acids (same as Example 1), and the combined fumaric acid product of Example 18 containing 10% uncombined fatty acid and 4% combined fumaric acid was made into a size according to the method of Examples 9-17.

Examples 37-56 For the sizing comparison, the 3% emulsions were prepared in a conventional manner and used according to the following procedure:

Bleached sulfite pulp was beaten to a Schopper-Riegler freeness of 750:10 cc. at 4.5% pulp consistency. This pulp was diluted to 2.5% consistency and the pH adjusted to pH 7. The proper amount of size was added as a 3% aqueous emulsion. Sufiicient papermakers alum was added to lower the pH of the slurry to about 4.3. The stock was then diluted to 0.25% consistency with pH 4.5 Water containing 5 ppm. aluminum ion as alum. Sheets of paper were made in a Noble and Wood handsheet machine at 0.025% consistency using pH 4.5 Water contain- TABLE 3 60 Photometer Sizing Stormer Seconds Standard Example Viscosity Feather Ink Example No. of Size Product or Rosin Source Alcohol Used to Stoichiometric or Type Size of 80% N 0. Used 1 From Which Size Prepared Prepare Resin Excess Alcohol 2 Total $0.11 0.75% 2.25% SZes Size Size (poises) 19 Example 9 Glycerin Stolchiometric.. Untortified 70 257 20 Example 10. Pentaerythritl do .do 18.9 79 268 21 Example 11.. Abitol do 48 248 22 Example 12 Sitoster l do 20. 0 S4 315 23 Example 13.- Glycerin. Ewe 64 280 24 Example 14. Pentaerythritol dn 77 269 25 Example 15 Abitol fl 71 280 26 Example 16 Sitoster do 87 328 Unmodified tall oil rosin 31. 6 56 228 Blend of rosin and fatty acid 170 1 Examples 19-26 contain a total of 10% fatty acid (free plus esterified). Example 35 has 10% free fatty acid.

2 Each resin was prepared with either the stcichiometric or 10% in excess of the st acid present.

3 Registered Hercules trademark.

oichiornetric amount of alcohol necessary to esterify all the fatty TABLE 4 Photometer Sizing Seconds Standard Example Product or Rosin Source From Alcohol Used to Stoichiometric or Feather Ink Example No. Nqj ofdS ize Which Size Prepared Prepare Resin Excess Alcohol 1 Type Size 0.75% 2.25% Size Size 27 Example 9 Glycerin Stoichiometric. Fortified 4 166 234 28 Example 10 Pentaerythritol .do .do 163 277 29 Example 11- Abitol dn do 138 191 30 Example 12 Sitosterol .do .do 180 306 31 Example 13 Glycerin. 10% Excess- 180 318 32 Example 14 Pentaerythritol -do do 180 282 33 Example 15 Abitol do 149 258 34 Example 16 Sitostet n n 174 392 Unmodified wood rosin- 150 310 36 Blend of rosin and fatty acid o 100 180 1 Examples 27-34 contain a total of 10% fatty acid (free plus esterified). Example 36 has 10% free fatty acid. 2 Each resin was prepared with either the stoichiometric or 10% in excess of the stoichiometric amount of alcohol necessary to esterify all the fatty acid present.

3 Registered Hercules trademark for a mixture of hydroahietyl alcohols. 4 The iortifier is present in the amount of 4% of the solids content as combined turmeric acid.

What I claim and desire to protect by Letters Patent is:

1. The. method of preparing a sizing composition from a mixture of rosin and from about 3% to about 13% by weight, based on the weightof rosin, of higher fatty acids which comprises reacting the mixture with a sufficient amount of an alcohol selected from the group consisting I of pentaerythritol, dipentaerythritol, polypcntaerythritols, trimcthylolethane, trimethylolpropane, hydroabietyl a1- cohols and beta-sitostcrol to esterify at least about of the fatty acids present in the mixture and then at least partially neutralizing the resulting product with aqueous alkali.

2. The method of preparing a sizing composition from a mixture of rosin and from about3% to about 13% by weight, based on the weight of rosin, of higher fatty acids which comprises reacting the mixture with an alcohol sclcctcd from the group consisting of pcntaerythritol, dipcntae'rythritol, polypcntaerythritols, trimcthylolethane, trimcthylolpropane, hydroabictyl alcohols and beta-sitesterol in an amount such that the ratio of cquivalents of hydroxyl to fatty acid carboxyl is from about 0.8 to 2.0,

- and then at least partially neutralizing the resulting product with aqeuous alkali.

3. The method of preparing a sizing composition from a mixture of rosin and higher fatty acids which comprises reacting the mixture with an alcohol selected from the group consisting of pentacrythritol, 'dipentaerythritol, polypcntaerythritols, trimcthylolcthanc, trimethylolpropane, hydrobictyl alcohols and bcta-sitosterol in an alkali, the fatty acid content of said sizing composition being from about 3% to about 13% by weight, based on the weight of rosin.

4. The method of preparing a sizing composition which comprises adding to rosin a higher. fatty acid which has been reacted with an alcohol selected from the group consisting of pcntacrythritol, dipentacrythritol, polypentaerythritols, trimethylolcthanc, trimethylolpropanc, hydroabietyl alcohols and bcta-sitosterol in an amount such that the ratio of equivalents of hydroxyl to fatty acid carboxyl is from about 0.8'to 2.0, and then at least partially neutralizing the resulting product with aqueous alkali, the

fatty acid content of said sizing composition being from about 3% to about 13% by weight, based on the weight of.

I'OSlIl.

5. The method of preparing a sizing composition which comprises adding to rosin a higher fatty acid which has been esterified with an alcohol selected from the group consisting of pentaerythritol, dipcntacrythritol, polypentaerythritols, trinicthylolethanc, trimcthylolpropanc, hydroabictyl alcohols and beta-sitostcrol in an amount such that the ratio of equivalents of hydroxyl to fatty acid carboxyl is from about 0.8 to 2.0, and then partially neutralizing the resulting product with aqueous alkali, the fatty acid content of said sizing composition being from about 3% to about 13% by weight, based on the weight of rosin.

6. The method in accordance with claim 1 wherein said higher fatty acids are derived from tall oil.

7. The method in accordance with claim 1 wherein the rosin is also. reacted with from one-twentieth to one mole per mole of rosin of an aliphatic dibasic acidic dienophile containing the group 8. The method in accordance with claim 1 wherein the alcohol is pentaerythritol.

9. The method in accordance with claim 1 wherein the alcohol is glycerol.

10. The method of claim 1 wherein the alcohol is betasitosterol.

11. The method of claim 1 wherein the alcohol is a hydroabietyl alcohol.

12. The method of claim 1 wherein the alcohol is dipentaerythritol.

13. The method of claim 1 wherein the alcohol is a polypentaerythritol.

14. A paste rosin size comprising a partially neutral: ized mixture of rosin and reaction product of a higher fatty acid and an alcohol selected from the group consisting of pentaerythritol, dipentaerythritol, polypentaerythritols, trimethylolethane, trimethylolpropane, hydroabietyl alcohols and beta-sitosterol, the fatty acid content of such reaction product including free and combined fatty acids being from about 3% to about 13% by weight, based on the weight of rosin.

15. A paste rosin size comprising a partially neutralized mixture of rosin and reaction product of a higher fatty acid and an alcohol selected from the group consisting of pentaerythritol, dipentaerythritol, polypentaerythritols, trimethylolethane, trimethylolpropane, hydroabietyl alcohols and beta-sitosterol, the amount of alcohol being such that the ratio of equivalents of hydroxyl to fatty acid carboxyl is from about 0.8 to 2.0, the fatty acid content of such reaction product including free and combined fatty acids being from about 3% to about 13% by weight, based on the weight of rosin.

16. A dry rosin size comprising a substantially completely neutralized mixture ofrosin and reaction product of a higher fatty acid and an alcohol selected from the group consisting of pentaerythritol, dipentaerythritol, polypentaerythritols, trimethylolethane, trimethylolpropane, hydroabietyl alcohols and beta-sitosterol, the

17. The method of sizing paper which comprises form- 7 ing an aqueous suspension of paper pulp, adding thereto an aqueous dispersion of a sizing composition obtained by (l) reacting a mixture of rosin and from about 3% to about 13% by weight, based on the weight of rosin, of a higher fatty acid with an alcohol selected from the group consisting of pentaerythritol, dipentaerythritol, polypentaerythritols, trimethylolethane, trimethylolpropane, hydroabietyl alcohols and beta-sitosterol and (2) partially neutralizing the resulting product with aqueous alkali, forming the resulting pulp suspension into a sheet, and drying the sheet.

.18. Paper sized with from about 25% to about 5% by Weight, based on the weight of paper, of a size obtained by reacting a mixture of rosin and from about 3% to about 13% by weight, based on the weight of rosin, of a higher fatty acid with an alcohol selected from the group consistnig of pentaerythritol, dipentaerythritol, polypentaerythritols, trimethylolethane, trimethylolpropane, hydroabietyl alcohols and beta-sitosterol, and then partially neutralizing the resulting product with aqueous alkali.

References Cited by the Examiner UNITED STATES PATENTS 1,882,680 10/1932 Wieger 106-238 2,420,926 5/ 1947 Anderson 106-219 2,744,889 5/1956 Gayer 106-219 2,881,084 4/1959 Watkins 106-219 XR 2,995,483 8/1961 Bonzagni 106-219 3,044,890 7/1962 Boughton et a1 106-238 FOREIGN PATENTS 519,984 12/1955 Canada.

ALEXANDER H. BRODMERKEL, Primary Examiner. MORRIS LIEBMAN, Examiner.

I. E. CARSON, J. B. EVANS Assistant Examiners. 

1. THE METHOD OF PREPARING A SIZING COMPOSITION FROM A MIXTURE OF ROSIN AND FROM ABOUT 3% TO ABOUT 13% BY WEIGHT, BASED ON THE WEIGHT OF ROSIN, OF HIGHER FATTY ACIDS WHICH COMPRISES REACTING THE MIXTURE WITH A SUFFICIENT AMOUNT OF AN ALCOHOL SELECTED FROM THE GROUP CONSISTING OF PENTAERYTHRITOL, DIPENTAERYTHRITOL, POLYPENTAERYTHRITOLS, TRIMETHYLOLETHANE, TRIMETHYLOLPROPANE, HYDROABIETYL ALCOHOLS AND BETA-SITOSTEROL TO ESTERIFY AT LEAST ABOUT 50% OF THE FATTY ACIDS PRESENT IN THE MIXTURE AND THEN AT LEAST PARTIALLY NEUTRALIZING THE RESULTING PRODUCT WITH AQUEOUS ALKALI. 